ROME (AP) – U.S. Defense Secretary Ash Carter said Wednesday the U.S.-led coalition has not agreed to cooperate with Russian Federation in the fight against the Islamic State and no collaboration is possible as long as Moscow continues to strike other targets.

“The Russian defence ministry has answered the demands of the Pentagon and is examining in depth American proposals on coordinating operations”, Russian news agencies quoted defence ministry spokesman Igor Konashenkov as saying.

“We benefit from this war and these (rival) coalitions, ‘ he said in a conversation via Skype, speaking on condition of anonymity because he is not authorized to talk on the group’s behalf”.

USA and Russian officials held discussions last week – at Russia’s request – on a mechanism to avoid accidents between warplanes flying over Syria. The meeting lasted for 90 minutes, but the men “disagreed on the role SyrianPresident Bashar al-Assad will have in resolving the civil conflict there”. The airstrikes were clearly meant to tip the area to the government’s favor, he added.

Russia’s military operation in Syria has provoked a strong reaction from the terrorist groups, Syrian information minister Omran al-Zoubi has said, as cited by the Syrian TV.

Antonov saidhis ministry was ready to establish different types of working groups with any interested country to prevent new problems similar to the Russian aircraft’s violation of Turkish airspace.

“I’m convinced that not only airborne should be used there, but also infantry, because the faster we finish off ISIS, the more peacefully we’ll live across the territory of global community,” he said.

“You can’t fight (the Islamic Stategroup) from the air”.

The tensions came as USA officials reported intensified Russian activity in apparent preparation for a few form of ground offensive against rebel-held areas of northern Syria and as they noted indications from a senior Russian official that Russia is planning to send ground forces to join the combat in Syria.